An L-shaped orange mounting structure with two white reservoirs on top, a set of pumps on the outer bottom edges, and a membrane cell bolted together in the center. The parts are connected by a series of transparent tubes.

Open Source Residential Energy Storage

August 15, 2024 by 20 Comments

Battery news typically covers the latest, greatest laboratory or industry breakthroughs to push modern devices further and faster. Could you build your own flow battery stationary storage for home-built solar and wind rigs though?

Based on the concept of appropriate technology, the system from the Flow Battery Research Collective will be easy to construct, easy to maintain, and safe to operate in a residential environment. Current experiments are focusing on Zn/I chemistry, but other aqueous chemistries could be used in the future. Instead of an ion exchange membrane, the battery uses readily attainable photo paper and is already showing similar order of magnitude performance to lab-developed cells.

Any components that aren’t off-the-shelf have been designed in FreeCAD. While they can be 3D printed, the researchers have found traditional milling yields better results which isn’t too surprising when you need something water-tight. More work is needed, but it is promising work toward a practical, DIY-able energy storage solution.

If you’re looking to build your own open source wind turbine or solar cells to charge up a home battery system, then we’ve got you covered. You can also break the chains of the power grid with off-the-shelf parts.

Australia’s Controlled Loads Are In Hot Water

August 15, 2024 by 125 Comments

Australian grids have long run a two-tiered pricing scheme for electricity. In many jurisdictions, regular electricity was charged at a certain rate. Meanwhile, you could get cheaper electricity for certain applications if your home was set up with a “controlled load.” Typically, this involved high energy equipment like pool heaters or hot water heaters.

This scheme has long allowed Australians to save money while keeping their water piping-hot at the same time. However, the electrical grid has changed significantly in the last decade. These controlled loads are starting to look increasingly out of step with what the grid and the consumer needs. What is to be done?

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Help The LEGO Camera Become A Reality

August 15, 2024 by 9 Comments

Some time over a year ago, we told you about a camera. Not just any camera, but a fully-functional 35mm film camera made entirely of LEGO, and with a pleasingly retro design into the bargain. It’s the work of [Zung92], and it can be found on the LEGO Ideas website.

You might now be asking why we’re talking about it again so soon, and the answer comes in its approaching the deadline for being considered by LEGO for a set. Projects on the Ideas website move forward when they achieve 10,000 supporters, and this one’s just shy of 8,000 with a month to go. We like this project and we think it deserves to see the light of day, and perhaps with your help it can.

When we covered this project last time we lamented the lack of technical detail, so we’re pleased to see a glimpse inside it as part of a manual uploaded to the updates page. We’d be the first to remark that with its LEGO part plastic lens and quarter-frame pictures it won’t be the best camera ever, but that’s hardly the point. Cameras like this one are a challenge, and it seems as though this one is perfect for the competition with a difference.

Unusual Tool Gets An Unusual Repair

August 15, 2024 by 25 Comments

In today’s value-engineered world, getting a decade of service out of a cordless tool is pretty impressive. By that point you’ve probably gotten your original investment back, and if the tool gives up the ghost, well, that’s what the e-waste bin is for. Not everyone likes to give up so easily, though, which results in clever repairs like the one that brought this cordless driver back to life.

The Black & Decker “Gyrodriver,” an interesting tool that is controlled with a twist of the wrist rather than the push of a button, worked well for [Petteri Aimonen] right up until the main planetary gear train started slipping thanks to stripped teeth on the plastic ring gear. Careful measurements of one of the planetary gears to determine parameters like the pitch and pressure angle of the teeth, along with the tooth count on both the planet gear and the stripped ring.

Here, most of us would have just 3D printed a replacement ring gear, but [Petteri] went a different way. He mentally rolled the ring gear out, envisioning it as a rack gear. To fabricate it, he simply ran a 60° V-bit across a sheet of steel plate, creating 56 parallel grooves with the correct pitch. Wrapping the grooved sheet around a round form created the ring gear while simultaneously closing the angle between teeth enough to match the measured 55° tooth angle in the original. [Petteri] says he soldered the two ends together to form the ring; it looks more like a weld in the photos, but whatever it was, the driver worked well after the old plastic teeth were milled out and the new ring gear was glued in place.

We think this is a really clever way to make gears, which seems like it would work well for both internal and external teeth. There are other ways to do it, of course, but this is one tip we’ll file away for a rainy day.

Autonomous Boat Plots Lake Beds

August 14, 2024 by 5 Comments

Although the types of drones currently dominating headlines tend to be airborne, whether it’s hobbyist quadcopters, autonomous delivery vehicles, or military craft, autonomous vehicles can take nearly any transportation method we can think of. [Clay Builds] has been hard at work on his drone which is actually an autonomous boat, which he uses to map the underwater topography of various lakes. In this video he takes us through the design and build process of this particular vehicle and then demonstrates it in action.

The boat itself takes inspiration from sailing catamarans, which have two hulls of equal size connected above the waterline, allowing for more stability and less drag than a standard single-hulled boat. This is [Clay]’s second autonomous boat, essentially a larger, more powerful version of one we featured before. Like the previous version, the hulls are connected with a solar panel and its support structure, which also provides the boat with electrical power and charges lithium-iron phosphate batteries in the hull. Steering is handled by two rudders with one on each hull, but it also employs differential steering for situations where more precise turning is required. The boat carries a sonar-type device for measuring the water depth, which is housed in a more hydrodynamic 3d-printed enclosure to reduce its drag in the water, and it can follow a waypoint mission using a combination of GPS and compass readings.

Like any project of this sort, there was a lot of testing and design iteration that had to go into this build before it was truly seaworthy. The original steering mechanism was the weak point, with the initial design based on a belt connecting the two rudders that would occasionally skip. But after a bit of testing and ironing out these kinks, the solar boat is on its way to measure the water’s depths. The project’s code as well as some of the data can be found on the project’s GitHub page, and if you’re looking for something more human-sized take a look at this solar-powered kayak instead.

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The experimental setup for entanglement-distribution experiments. (Credit: Craddock et al., PRX Quantum, 2024)

Entangled Photons Maintained Using Existing Fiber Under NYC’s Streets

August 14, 2024 by 12 Comments

Entangled photons are an ideal choice for large-scale networks employing quantum encryption or similar, as photons can use fiber-optical cables to transmit them. One issue with using existing commercial fiber-optic lines for this purpose is that these have imperfections which can disrupt photon entanglement. This can be worked around by delaying one member of the pair slightly, but this makes using the pairs harder. Instead, a team at New York-based startup Qunnect used polarization entanglement to successfully transmit and maintain thousands of photons over the course of weeks through a section of existing commercial fiber, as detailed in the recently published paper by [Alexander N. Craddock] et al. in PRX Quantum (with accompanying press release).

The entangled photons were created via spontaneous four-wave mixing in a warm rubidium vapor. This creates a photon with a wavelength of 795 nm and one with 1324 nm. The latter of which is compatible with the fiber network and is thus transmitted over the 34 kilometers. To measure the shift in polarization of the transmitted photos, non-entangled photons with a known polarization were transmitted along with the entangled ones. This then allowed for polarization compensation for the entangled photos by measuring the shift on the single photons. Overall, the team reported an uptime of nearly 100% with about 20,000 entangled photons transmitted per second.

As a proof of concept it shows that existing fiber-optical lines could in the future conceivably be used for quantum computing and encryption without upgrades.

Handsome Sim Racing Button Box Is A Super Easy Build

August 14, 2024 by 8 Comments

Sim racing is a lot more complex than playing Need For Speed 3: Hot Pursuit. You need buttons for all kinds of stuff, from headlights to brake balance to traction control. If you want to control all that in an intuitive and realistic manner, you’ll want to build yourself a decent button pad like [Chris Haye] has done. It’s surprisingly easy, too!

Very cool.

[Chris] is quite a serious racer, and needed four button boxes. He wanted to do this on the cheap, so he decided to build his first three boxes around the Zero Delay Arcade USB Encoder, a cheap controller board available on eBay for around £7. Arcade buttons were sourced off Amazon to populate the black project boxes which acted as the housings.

His final button pad looks straight out of a GT3 race car, but it’s the simplest of the bunch. It’s literally just a USB numpad with a carbon vinyl wrap applied and some home-printed labels. One suspects the feel isn’t particularly high-quality but the look is top tier. If you’re a streamer that wants to build a hardcore-looking setup, this is a great way to go.

[Chris] estimates that each box took maybe an hour to build, tops. It’s a great example of solution-focused design. He could have gotten out his own microcontroller and done a custom PCB and all that, and the results surely would have been good. But it would have taken far longer! It’s hard to beat the speed of wiring together Amazon arcade buttons with the Arcade USB Encoder’s pre-terminated wire harness. If you’re more interested in sim racing than building button boxes, it’s a great way to do a custom pad fast.

Best of all? [Chris] says he managed to put these all together for £60—quite a feat of bargain engineering. We’ve featured some other builds along these lines before, too—even using vintage aircraft controls! Video after the break.

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